What Theymos says is largely correct. However, when a debit or credit card payment is disputed the person disputing it must give a reason. Following your dispute of the transaction the card issuer will ask the merchant for an explanation.

1. So you buy a gold ring described as 14ct paying with your card. When it arrives you find it is only 10ct , you try to resolve it but the seller wont respond, you raise the dispute, card issuer says to merchant why did you send wrong item? retailer says it's the only one in stock and who will notice the difference, Card company finds in your favour and will deduct the sale from the merchant and refund you as it is plainly the merchants fault.


2. You order a suite for a wedding and pay on your Card, it's a great suite perfect fit etc, after the wedding your a bit short of cash so you send it back saying you don't like it and it wont fit and want a refund The retailer says sorry you wore it and we wont refund. You raise a dispute-the card company asks the merchant for their side.  Merchant reply's "you wore it to the wedding and look here you are on FB looking happy".  Card company declines your refund.

In both cases the card issuer will decide ( there are appeal avenues if you think the decision is unjust)

So back to crypto: as you can see in 1. you didn't get your goods-you payed for some BTC and you didn't receive it. Raise a dispute and the person accepting the card payment will have it taken back and you would be refunded-in theory. to to the seller
In case 2 you buy some BTC then 10 minutes later change your mind, the seller says sale is final and no refunds but we will buy them back at a discount rate-we will give you 50% of what you paid, you raise a dispute with card company-they ask seller what was agreed  they say you purchased the Btc then changed your mind. OK says card company keep your money, goes back gto you and says sorry they are correct- The good news is you still have the btc

The other payment systems will have something along the lines above,
Just be careful the main danger is that a stolen Credit/debit card was used and in that case provided you accepted  it in good faith you should still be ok